Brush-holder and brush.



No. 673,516. Patented May 7, IQDI. C. A. ECK.

BRUSH HOLDER AND BRUSH.

[Application filed Nov. 24, 1900.)

(No Model.)

j .WQQNESSES: 4 INVENTOR I W 7 AW 2W! 0 ,6 in BY ATTORNEY m: uonms PETERS coy. Pncnmu'rua, wAsumamu. n, c.

UNITED STATES PATE T OFFICE.

CHARLES A. EOK, OF NEWARK, NEW JERSEY.

BRUSH-HOLDER AND BRUSH.

SPECIFICATION forming part of Letters IPatent No. 673,516, dated May '7, 1901.

Application filed November 24, 1900. Serial No. 37,659. (No model.) I

To all whom it may concern:

Be it known that I, CHARLES A. EcK, a subject of the King of Sweden and Norway, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Brush- Holders and Brushes, of which the following is a specification.

My invention relates to brush-holders and brushes for dynamo-electric machines; and its object is to provide a brush-holder and brush which will keep the latter in contact with the commutator with its full bearingsurface and at the same time have the pressure of the holder evenly distributed at all times, so as to wear the brush evenly, prevent sparking, and generally to yield a higher efficiency in its operation.

Other objects will appear farther on in the specification; and the invention consists of the hereinafter-described means pointed out in the claims.

In operating dynamo-electric machines it is of the utmost importance that the entire bearing-surface of the brush should be kept in contact with the commutator, so as to prevent uneven wear of the said brush, which is undesirable, as a sharp edge or ridge is sometimes formed thereby, which cuts into the commutator, and also for the reason that unless full contact is made the brush acts as an unsatisfactory conductor, breaking the current and causing sparking. As the commutator is a revolving body cylindricalin form, it presents a continuously-moving arc-shaped friction-surface to the brush, and the latter to make full and perfect contact must needs be in a position where the center line of its arc-shaped bearing-surface will at all times be coincident with a line radiating from the center of the circle describing the contacting arc of the commutator. In other words, the bearing-surface of the brush must at all times be concentric with the contacting arc of the commutator. In practice it has been found that even although the brush is perfectly adjusted and the pressure of the brush-holder evenly distributed when'inserted into the latter, registering perfectly with its entire bearing-surface, it soon wears down unevenly owing to the somewhat irregular motion of the commutator, and the unsatisfactory condition stated above results. Heretofore it has been attempted to prevent this uneven contact, pressure, and wear by supporting the brush rigidly and in such a manner that it is impossible for it to move circumferentially of the commutator. My invention, on the other hand, contemplates the supporting of the brush loosely, as with a joint, so as to allow enough play to enable the brush to adapt itself to any irregular motion on the part of the commutator, so that its bearing-surface will at all times be concentric with the contacting arc of the commutator. This may be accomplished either by supporting the brush loosely on a hinge or ball-and-socket joint'or by supporting the brush rigidly on a looselypivoted brush-holder admitting of movement.

In the drawingslhave embodied my invention in various forms, indicating the different constructions which may be used; but it will of course be understood that any and all constructions may be used embodying the invention herein set forth and that I do not limit myself to the exact means shown. I

In the said drawings, Figure 1 shows a commutator with abrush-holder and brush embodying my invention. Fig. 2 is a side view of the same. Figs. 3, 4, 5, and 6 are detail views. Figs. 7, 8, 9, 10, and 11 are modifications.-

Similar numerals of reference indicate corresponding parts in the different views.

I shall describe a brush-holder, brush, and adjacent elements embodying my invention and afterward point out the novel features in the claims.

1 indicates an armature-shaft with the commutator 2 mounted upon it.

3 is a stationary bar attached in any suitable manuer to the motor and adapted to fit into the aperture 4. of the detachable holder 6 and fastened there by means of the screw '7, one surface 8 of the bar being made fiat for that purpose. This holder 6 has a downwardly-extending projection 6 which carries the U-shaped spring 9, having fastened at its other end the bearing-joint 10, having the curved portion 10, adapted to fit into the brush 11, provided with the correspondinglycurved concavity 11. This concavity may extend only partially across the brush, as shown in Figs. 1 and 3, or it may have the concavity running its entire width, as shown.

in Fig. 4. To prevent displacement, the curved portion 10* may be provided with a pin 10 and the brush with a corresponding able and is adapted to act as a guide for the bearing-joint 10, the latter having to that end the aperture 10.

In connection with the brush and the bearing-joint there is still another point to be noted. The brush 11 is provided with a slot or concavity 11, extending all the way across the rear face, so that when the said brush is worn down to this slot it will break or split and. drop off and the. motor stop, thus forcibly calling attention to the necessity'of inserting a new brush, while the bearing-joint 10is prevented from flying against the commutator by the button or head 6 The spring 9 is also of a peculiar construction. It has been found that if a spring is made of a material Which is a good conductor, such as copper, its elasticity is quickly destroyed bythe electric currentpassing through the same. Forthis reason I make my spring of two layers of material having difierent characteristics, one a good conducting material, such as copper, and the other of a material of indifferent conductivity and whose elasticity is not destroyed by the'current, such as steel. The conducting and elastic layers, respectively 9 and 9 are so arranged that the c onductinglayer contacts with the bearing-joint 10 and the portion 6 as shown, so that the circuit is uninterrupted.

In Fig. 7 the peripheral movement of the brush is accomplished by forming the brush with a socket 12 and the holder with a rounded portion 12 adapted to fit into the same. In thisinstance the pressure is exerted by means of the spring 12 pressing on the movable member 12, sliding in the stationary member 12, the tension of the spring being regulated by means of the pin 12 In Fig. 9 the brush is formed with a triangular ridge 13, extending transversely, and

the bearingjoint with a triangular incision 13, while in Fig. 10 the .brush has a coneshaped portion 14., the bearing-joint having correspondingly a cone-shaped socket 145*.

' In Fig. 8 the brush has a triangular incision 15 extending transversely and adapted to receive the dog 15*, whose tension is regulated by a spring 15", adjustable by means of the handle 1, adapted to be inserted into the notches 15 in a well-known manner.

In Fig. 11 the brush is shown as being held rigid, while the holder is pivoted, as at 16, whereby the same result of peripheral play is obtained.

Various other forms may of course be used to suit different requirements; but

What I claim, and desire to secure by Let- V ters Patent, is-

1. The combination of a commutator and a brush adapted to break or split when worn to a predetermined but variable point, with a brush-holder adapted to support said brush, means carried by said brush-holder adapted to hold the brush under tension against the commutator, and means for limiting the movewill not contact with the commutator when the brush breaks, substantially as described.

2. The combination of a commutator and a brush adapted to break or split when worn down to a predetermined but variable point, with a brush-holder, a bearing-joint carried by said brush-holder adapted to support the brush, means for holding saidbearing-joint under tension against the brush, and means for preventing the contact of the bearingjoint with the commutator when the brush breaks, substantially as described.

- 3. Inabrush-holder,atension-springadapted to act as axconductor of the current, comprising two or more superposed layers of different character of materials, the current passing through one layer while the elasticity of the spring is maintained by the other layer, substantially as described.

- m'ent of the tension. means so. that the latter 4. In a brush-holder,a tension-spring formed of two superposed layers of materia1,one layer acting as a conductor of the current the other layer preserving the elasticity of the spring, substantially as described.

5. In a brush-holder a tension-spring formed of two superposed layers, one layer being of a good conducting material, the other layer of a material substantially indifferent to the electric current, so as to preserve the elasticity of the spring, substantially as described.

6. In a brush-holder a tension-spring formed with a conducting and a relatively indifferent conducting layer, for the purposes as set forth, substantially asdescribed.

. 7. In a brush-holder, the combination of a holder, a bearing-joint, a conducting tensionspring formed with a conducting and a relatively indifferent conducting layer connecting the two and so arranged that the conducting layer is in direct contact with both the holder and the bearing-joint, substantially as described.

8; In a brush-holder, a stationary support, a detachable holder on said support, a downwardly-extending projection carried by said support, a U-shaped tension-spring on said projection, a bearing-joint for supporting the brush carried by said spring, an adjustable horizontal guiding-bar carried by the holder at its upper end, an aperture in said bearingjoint for the insertion of said guiding-bar, and means carried by said bar limiting the movement of the bearing-joint, substantially as described. I

Signed at Newark, in the county of Essex and State of New Jersey, this 8th day of N 0- vember, A. D. 1900.

CHARLES A. EoK.

Witnesses:

FREDERICK T. R. GRUETT, FREDERICK R. LATTUS. 

